The Hormone Assay Subcore provides investigators access to a number of analytical methods related to the measurement of hormones in biologic fluids. The subcore provides space, equipment and personnel for sample analysis and method development. Investigators pay a charge to cover the cost of supplies and pro-rated service contracts. The analyses available include l) insulin, 2) glucagon, 3) cortisol, 4) catecholamines, 5) growth hormone, and 6) c-peptide. Some "micro" assays are available for the analysis of hormone levels in very small volumes of plasma or blood. Some assays are designed to measure hormones in particular species. Investigators identified as users of this subcore project an increased demand for about half of the services offered, and a constant demand for the rest of the assays.